Photographic process for converting black-and -white or monochrome pictures into multicolor pictures



Patented Feb. 8, 1949 TENT QF'FICTE PHOTGGRAPHIC PROCESS FOR CONVERT- ;KNG BLACK-AND -VVHITE OR MONO- CHRGME PICTURES INTO MULTICOL'OR PICTURES RichardM. ,Hafi, Binghamton, N. Y., assignorto General Anil ine & Fihn Corporation,New York, -N.,Y., a corporation of Delaware No Drawing. Original applicationAugust 31, 1944, Serial $10,552,209. Divided and thisaplpiicationMay 18, .1946, Serial No. 670,8 9

10Qlaims. (Cl. 95--2) This invention relates to color, photographyand more particularly to a process of converting black and white or monochrome drawings into colored drawings.

In preparing colored drawingsfrom an original black line or monochrome drawing, theprocess mployed is to opy orphotosrapha .black a White or monochromedrawing on a photographic film. Afterdeyelopinent, washing anddryingof theexposed filnrthe negative is ,laid on aglass illuminated from, below and dye coating solutions applied to thetransparent .lines andareas of ,ithenegative which are to appear in color in the finished print. .Thecolors of thedyesolutions employed.- are complementary .to the colors desired inthe finalprint. Toobtain in thefinal prinna line or areaof any color, .for example, green, the line orarea inlthenegativeis dyed with a color complementary togreen, namely, magenta. Thesystern maybe bestunderstood by referencelto. the followingtable:

I Color desired in finished Color of .dyeepplied to film negative reproduction v Red;

Cyan (Blue-Green). Yellow n. "Blue. Gr

een Magenta. Cyan (l3luc-Green) 'R Blue Magenta I Green. Black No dye needed. The negative is left 'uncolored;

V A photographic paper consisting of three emulsions coatedcon -.a-.support, each emulsion layer sensitiveto'light of one of-the co1ors,=reid,1green M and blue, and each layer containing. color forrr ing com-ponndis exposed inaprinting-frame in contact withthe emulsionsurface of the colored negative .to white light with or without the use of filters over-the light source. The'd-yesin the lines-or areas of thenegati-ve serveas color filters, which are ingeneral adequate'to print lines of satisfactory color and purity without the use of additional 'filters. A single exposure is .sufiicient to: print all of the colored lines. After exposure,

therphotographiccolor paper is-then'deve1oped in a p-phenylene-diamine-type developer, the reaction products of which couple with the-color forming compounds contained inthe emulsion layers of the photographic colorpaperfto give 9 V al plication ofthe-dye coating compositions to tlie transparent lines or areas of l the negative' which are to'appearin color in the finished print; The aqueous or alcohol solutions of the dyes'previously used are not satisfactory "ior'coloringthe negatives, since they are-difiicuIttoappIyinsufficient density with reasonable speed. Furthermore, crystallizationbfthe dyetakes place upon drying. These dye solutions also havefa-tendency to-run, afterapplication, into unevenareasresulting in the formation of areas of, unequal density, so that-uneven color lines or areas are obtaineclin the finished print,

It is an object of'thepresent' invention to-overcome these and other undesirable characteristics and disadvantages, and 'to provide improveddye coating compositions, whereby colored negatives of desirable characteristic are'obtained.

A further object isto providea simplified process of converting black and white or monochrome drawings into multicolor photographs.

Other objects and ad vantag''es of this invention Will be apparent by reference to the foregoing specification, in which its preferred details and embodiments are described.

The objects outlined above are g-accoinplished by employing dye coatin g cornpositions ofithejollowing'general composition Grams Water soluble ,dye o 1-10 15 to aqueous solutionbf complex sodium borophosphate 501- The complexsodium borophosphate referred to in the above general composition is either 'a noncrystalline Water soluble-glass solid obtained by fusingv analkalimetal phosphate withan oxygen containing compound of boron -as -described in U. S. Patent 122 391958, :or a water. soluble viscous solution obtained'by heating aqueoussolutions of monosodinmphosphate and'an alkali .metal borate as described in U; S. *Patent '2;143,6.41; Thesolid content of :the aqueous solutions preparedby either method? may l-range gfrom .15- I to 35% or more b y weight. "The preferred :concentration for the purpose of thepresentyinvention is one that contains 15% by weight d-the solid complexsodiumborophosphate.

.In the .above general composition any com mercially available water. solubledyama-y be-employed. The-nature of the-dye is-immateriaLso one-as it sw tersqluble and ives thed sired colorimetric result. ,In. general, the .most ,satisfactor Wat .rso uble dye a o nd .inthe g oup of dyes classified under the usual constitutional headings, which are grouped in the following list:

Acridine dyes, e. g., Acridine Orange R. (C. I. #792) Phosphine 2G (C. I. #794) Euchrysine 2G (C. I. #797), etc., anthraquinone dyes, e. g., Alizarin Carmine (C. I. #1034), Erweco Alizarin Acid Red SB (C. I. #1036) Pseudopurpurin (C. I. #1043), etc., azine dyes, e. g., Neutral Red (C. I. #825), Neutral Violet (C. I. #876), Rosinduline G (C. I. #831), etc., monoazo dyes, e. g., Emin Red (C. I. #132), Metanil Yellow (C. I. #138), Eriochrome Phosphine R (C. I. #157), etc., nitro dyes, e. g., Victoria Yellow (C. I. #8), Naphthol Yellow (C. I. #10), Amiclo Yellow (C. I. #11), etc.., oxazine dyes, e. g., Brilliant Blue CC (C. I. #876), Chroma-zurine E (C. I. #879) etc., pyrazolone dyes, e. g., Fast Light Yellow (C. I. #636), Kiton Fast Yellow 3G (C. I. #645), Pyrazolorange G (C. I. #653), etc, stilbene dyes, e. g., Chlorazol Yellow GX (C. I. #620), Cotton Orange 6305 (C. I.

#625), Direct Fast Orange BGL (C. I. #633),

etc., thiazine dyes, e. g., Genthianine (C. I. #921), Methylene Azure (C. I. #923), Indochroinogen S (C. I. #930), and triphenyl methane dyes, e. g., Turquiso Blue G (C. I. #661), Acid Green (C. I.

#669). Xylene Blue AS (C. I. #673) and the like.

. The above dyes were selected because of their brilliancy of color. The preferred dyes from the above group, however, are those which effectively transmit a sharply isolated spectral band while eliminating undesirable transmissions of a secondary spectral band. Thus, for example, the red dye which may be a mixture of Anthraquinone Rubine and Tartrazine, transmits freely in the red wave length beyond 600 m and is subs tantial- 1y opaque to the spectral region below 600 m The green dye which may be a mixture of Anthraquinone Blue SE and Tartrazine N transmits freely in the green wave length between 500 and 600 mp and is substantially opaque to other spectral regions. mixture of Anthraquinone Blue SE and Fast Acid Violet B transmits freely in the blue wave length between 400 and 500 inn and is substantially opaque to the longer wave lengths of the spectrum. The orange dye such as Pyrazolorange G transmits above 500 ru and is substantially opaque to the shorter wave lengths of the spectrum. The magenta dye such as Anthraquinone Rubine transmits freely two bands. one in the blue region of 400-500 m and the other band in the red region above 600 mo and is opaque to the green region of the spectrum. The cyan dye such as Anthraquinone Blue SE transmits freely in the blue and green region between 400 and 600 m, and is likewise opaque to the longer wave lengths of the spectrum. The actual selection of the preferred dyes is made by colorimetric methods which are well-known to the art and need not be discussed herein, or by actually preparing the dye coating composition, coloring a negative and printing it out on color paper.

The cyan dyes suitable for forming red lines or areas in the finished print are, for example, Anthraquinone Blue SE (Schultz #861), Brilliant Alizarin Viridine F (Schultz #854) and Alizarin Cyanine Green F (Schultz #865).

The yellow dyes suitable for forming the blue lines or areas in the finished print are, for example, Pyrazolorange G (Schultz #747), Stilbene Yellow BGA (C. I. #622), Milling Yellow (Schultz #230), Erie Yellow Y (C. I. #365), Solantine Yellow FF (C. I. #814) Naphthol Yellow s (Schultz #7) and Tartra-zine N (Schultz #23);

The blue dye which may be a magenta dyes with yellow dyes.

The magneta dyes suitable for forming the green lines or areas in the finished print are, for example, Brilliant Congo G (Schultz #369), Geranine GL, Erie Pink 2B (C. I. #123), Rose Bengal N (Schultz #595) Brilliant Purpurine 4B (Schultz #368) and Brilliant Crocein B (Schultz #227).

Several red dyes may be obtained by blending Suitable greens may be obtained by blending cyan dyes with yellow dyes. Suitable blue-violets may be obtained by blending cyan dyes with violet or magenta dyes. Similarly, the hue of the single dyes, yellow, magenta and cyan, may be adjusted to the requirements of the color paper by blending two dyes together.

The amount of dye employed in each coating composition will depend upon the amount of the aqueous complex sodium loorophosphate used and the depth of shade required. The amount employed may range from 1 to 10 grams per 100 grams of the aqueous complex sodium borophosphate. The desirable proportions, however, are in the range of 3 to 5 grams per 100 grams of aqueous complex sodium borophosphate.

The aqueous solution of the complex sodium borophosphate acts as a vehicle for the dyes. The amount employed may range from 50 to 100 grams per 1-10 grams of the water soluble dye.

In carrying out the invention into practice the aqueous solution of the complex sodium borophosphate is heated gently at a temperature not exceeding 50 C. with stirring for a few minutes and then allowed to cool. In preparing the dye coating composition, a paste is made of the dye by mixing it with a small quantity of a warm aqueous solution of the complex sodium borophosphate until the dye is wetted. The remainder of the aqueous solution of the complex sodium borophosphate is then added and brought to the desired weight. Although substantially all of the water soluble dyes listed above are compatible with the aqueous solution of complex sodium borophosphate, a few isolated instance occurred where a slight difiiculty was encountered in completely dissolving the dye. In such a case I have found that by lowering the pH of the aqueous solution of the complex sodium borophosphate from about 7.0 to a pH ranging from 5.0 to 4.0 by the addition of a small quantity of a water soluble organic acid containing from 2 to 6 carbon atoms such as, for example, acetic, acrylic, citric, malonic, oxalic, tartaric and the like, solutions are obtained in which the dye is readily and completely dissolved. The amount of acid employed may vary from 5 to 15 parts. per 100 parts of the aqueous solution of the complex sodium borophosphate. Although any one of the acids listed above may be employed for lowering of the pH, the use of acetic acid, in view of its low cost, is preferred.

The following examples are illustrative of the manner in which compositions of this invention are prepared:

The aqueous solution of complex sodium borophosphate employed in Example II was purchased on the open market under the trade-name of A'bopon and presumably made according to the process described in U. S. Patent 2,143,641. The aqueous solution of complex sodium borophosphate employed in Examples I and III was prepared according to Example 7 of U. S. Patent 2,291,958 by fusing 2 mols of sodium hexametaphosphate with 3 mols of borax and shock-chilling the resulting melt. Fifteen grams of the glassy brought up to 100 cc.

ExAmeLE I ..Blue1vi.olet dye Grams Complex sodium borophosphate 15% solution I AnthraguinoneBlue Se (Schultz #861) Fast Acid 'VioletiB (Schultz #580). .1;

EXAMPLE II Yellow dye "Grams Complexsodium -borop-hosphate- 35% solu tion 50 Pyrazolorange G (Schultz #7547 .W W 2.0

'EXAMPLEIII" Magentmdye Grams Complex sodium -borophosphate15% solution .100 Brilliant Congo G (Schultz #369) 3 A-specificexamp'le of employing the above dye coating compositions in the preparation of a colored film negative-for "color printing is the following:

A-drawing of an 'electrical-circuitin in'dia ink was copied on ahigh-contrast photographicfilm so astozobtain :high densities and clean :White lines. After exposure, the film was developed in the nsual developing solution, fixed, washed and dried. "The dried negative was then'temporarily cemented emulsion downwards on a piece .of glass. The film negative andglass were then placed .on a light table in a.reasonably'levelposh tion. The light table Wasffitted with daylight fluorescent tubes in order .to obtain desirable color quality for, judgment of color densities. The film negativewas thenecleaned witha cloth moistened with ethyl alcohol 'in order tQprepare it for even dyeing.

The above blue-violet, yellow and magenta dye coating compositions were then applied evenly over the "white lines -=of the negative whichare to appear -as yellow blue and green "respectively in the final print. The dye coating solutions were appl-ied by means of --a small-spotting brush, the-sharp:needle p.oint-.ofz-which :wascut ofi,-so as td-cimfine the dye substantially: to the line .being colored; that :is, without .':substantially overlapping the white :line,- or iformingrareas Of'cBXGGSS dye adjoining the white line. One application with the brush fully charged with each of the dyes 'to "the'lines'being-colored was adequate to obtainsuificientcoljordensity. The applied dye coatingsolution was permitted to flow naturally in :order "to .obtain 'eve'n spreading; :Between colors. the brush-wasrrinsediin a:glass oi water and dried on'a cloth. After application offthe dyes, 3 130. 5 minutes wererequired for "thorough drying, following which the negative was removedfromthe glassfor printing.

, An examination. of the above coloredpnegative showed that theedye eoatings were thoroughly dry and did not crack or the dyes crystallize out. All the "colored lines "were satisfactorily smooth and even. The colored negative was then contact printed onia threesuperimposed emulsion layer photographic color .paper, {emulsion ytO emulsion in a printing frame,-siX-,f.e.et from-1a 50- watt frosted mazda lamp. Theiexposure time was approximately seconds. The exposed color ::paper was then "developed in a developer .ofithei'fellowing. composition: 1

- or 3 paper prints.

p -Aen-ino-diethylaniline l-li'll; ;;g-rams 2.0 Sodium carbonate Kanhydrous) d-o 50.0 Sodium mime-(anhydrous) do 2.0 Potassium bromide -dc 0.2 Water "to make liter =1 After bleaching, fixing, washing vanddrying,the resulting print showed- :no uneveness in the colored lines. All the colored lines weresmooth and pure color. 1

The photographic multilayer element (color paperlor other printing material used in car-ry ingout the processdescribed inthe present invention consists-of an integral tripack emulsion coated on either the usual paper base, oraolear cellulose acetate or nitrate film base, or in some cases;an opague white-film base. Each of the emulsion @layerspis sensitizedto one of the p ri-- mar-ycolors of light; namely, blue, green-and red. The top layer is blue sensitive. A rfilter layer, yellow in color and blue absorbing, lies under the-top layer. .Below this filter layer lies aggreen-sensitiveemulsion layer, andebelow this a red sensitive emulsion layer. Each of the three silver.-halide emulsion layers contain dye-forming compounds whichunite during the development of a silver image an aromatic amine developing agent to form adye with the oxidation product of the developing agent. As silver is also "formed during development, it must be removed after color development by treatment in:ableachfollowed by a bath of :sodium thiosulfate, :as :is well known to the art. 'A yellow dye "is formed in the blue sensitive emulsion; 'a magenta dye is l'orrned'in the green sensitive emulsion; and acyan dye is formed in the red sensitive emulsion. The combinations of these three printing primaries yield red, green, blue and black lines. Suitable methods for the prep-. arationof multicolor emulsion layers have been described --in- *the literature relating to color photography and are, therefore, not described here.

The 'dye coating compositions of the present invention are not limited to the coloring of a black-and'whitefilm negative given above, such being merely illustrative of the manner of employing the dye coating compositionsof this-invention. I

"Instead of coating black and white negatives, the dye coating-compositions of the present 'in" vention may be employed for making colored transparencies from blackand white or blueprint drawings. In this-process, a thin andfiat transparent'medium such as paper, organic ester of cellulose, superpolyamide, polyester or synthetic resin, is superimposed over a black and white ;or ;bl ue print :drawing, and the various lines ,or areas whichare to appearin color :are inked ,or 'coated with the dye coating compositions. .After dryingthetransparency, his then removed from the original drawing and printed on color paper as hereinabefore 1 described.

The dye coating compositions may aiso beemplayed for-retouching orrepairing damaged areas of colored photographs such as'transparencies The various dye coating com- DOSllJiQIIS-A'HQ'Y 'bB mixedeon a piece'of opalglass with a small brush to match the prevailing color ,oirthe area surrounding the "blemish. The dye is then applied with the brush to the blemish. On "drying, the dye will assume the surface charreadily detectable:

This application is a division of my co-pending application Serial No. 552,209 filed on August 31, 1944, now Patent No. 2,433,811 of Dec. 30, 1947.

While I have herein disclosed the preferred embodiments of my invention, I do not thereby desire or intend to limit myself solely to the specific examples, since it will be readily apparent to those skilled in the art, that the precise proportions of the materials utilized may be varied and other materials having equivalent chemical or physical properties may be employed if desired without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. The process of producing subtractively colored photographic prints which comprises photographing a monochrome image onto a photographic light-sensitive silver-halide emulsion, developing the exposed emulsion to a negative, coloring certain portions of the negative which are to appear in color in said subtractively colored print with a dispersion comprising:

. Grams l-35% aqueous solution of complex sodium borophosphate 50-100 Water soluble organic dye 1l0 said water soluble organic dye in said dispersion being of a color, complementary to that which is to represent the corresponding colored portion in said print and coloring other portions of said negative with a dispersion as aforesaid in which the water soluble organic dye is of a color dilferent from that of said first dispersion and complementary to that which is to represent the corresponding colored portion of said print, printing the resulting colored negative onto a photographic, multi-layer, light-sensitive emul sion, the layers of which are selectively sensitized to the red, green, and blue regions of the spectrum, each layer containing a color former capable of yielding a dye image complementary in color to that for which it is sensitized and developing the exposed layers by color forming development into a subtractively colored print.

2. The process as defined in claim 1 in which the aqueous solution of a complex sodium borophosphate is acidified with a water soluble organic acid containing from two to six carbon atoms to a pH ranging from 5.0 to 4.0.

3. The process as defined in claim 1 in which portions of the negative which correspond to portions of the print to be colored red are colored with a dispersion consisting of:

Grams Complex sodium borophosphate 15% aqueous solution 100 Anthraquinone Biue SE (Schultz #861) 3.0 Fast Acid Violet B (Schultz #580) 1.5

4. The process as defined in claim 1 in which portions of the negative which correspond to portions of the print to be colored blue are colored with a dispersion consisting of:

Grams Complex sodium borophosphate 35% aqueous solution 50 Pyrazolorange G (Schultz #747) 2.0

5. The process as defined in claim 1 in which portions of the negative which correspond to portions of the print to be colored green are colored. with a dispersion consisting of:

Grams Complex sodium borophosphate 15% aqueous solution Brilliant Congo G (Schultz #369) 3.0

6. A method of producing subtractively colored photographic prints which comprises coloring certain portions of a transparent sheet material which are to appear in color with a dispersion comprising:

Grams 15-35% aqueous solution of complex sodium borophosphate 50-100 Water soluble organic dye 1-10 said water soluble organic dye in said dispersion being of a color complementary to that which is to represent the corresponding colored portion in said print and coloring other portions of said transparent sheet material with a dispersion as aforesaid in whichthe water soluble organic dye is of a color difierent from that of said first dispersion and complementary to that which is to represent the corresponding colored portion of said print, printing the resulting colored sheet material onto a photographic, multi-layer, lightsensitive emulsion, the layers of which are-selectively sensitized to the red, green, and blue regions of the spectrum, each layer containing a color former capable of yielding a dye image complementary in color to that for which it is sensitized and developing the exposed layers by coicr forming development into a subtractively colored print.

7. The method as defined in claim 6 in which the aqueous solution of a complex sodium borophosphate is acidified with a water soluble organic acid containing from two to six carbon atoms to a pH ranging from 5.0 to 4.0.

8. The method as defined in claim 6 in which portions of the sheet material which correspond to portions of the print to be colored red are colored with a dispersion consisting of:

9. The method as defined in claim 6 in which portions of the sheet material which correspond to portions of the print to be colored blue are colored with a dispersion consisting of:

- Grams Complex sodium borophosphate 35% aqueous solution 50 Pyrazolorange G (Schultz #747) 2.0

10. The method as defined in claim 6 in which portions of the sheet material which correspond to portions of the print to be colored green are colored with adispersion consisting of:

Grams Complex sodium borophosphate 15% aqueous solution 100 Brilliant Congo G (Schultz #369) 3.0

' RICHARD M. HAFF.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Country Date Great Britain June 7, 1938 Number 

